VicRoads
SECTION706-INSTALLATION OR REPLACEMENT OF UTILITY INFRASTRUCTURE WITHIN ROAD RESERVES
##This section cross-references Section 173.
If Section 173 is relevant, it should be included in the specification.
If Section 173 is not included in the specification, all references to it should be struck out, ensuring that the remaining text is still coherent:
706.01DESCRIPTION
This section covers requirements for the installation or replacement of utility infrastructure (e.g.conduits, pipes, service pits, poles, aerial services/cables) within the road reserve of an arterial road or freeway, as shown on the drawings, or as specified.
706.02LEGISLATIVE FRAMEWORK
The management principles and practices applying to utilities and road authorities for the installation, maintenance, replacement and operation of utility infrastructure within road reserves are set out in the Road Management Act2004, Road Management (Works and Infrastructure) Regulations2005 and the Code of Practice for Management of Infrastructure in Road Reserves (Victoria Government GazetteNo.S269 Monday6October2008).
All planning, design and installation or replacement of utility infrastructure, as shown on the drawings, or as specified, shall be carried out in accordance with the requirements set out in the above legislative framework and the additional requirements specified in this section.
Any consultation required with, and authorisation required from, other authorities under relevant utility regulations and codes shall be the responsibility of the Contractor.
706.03POSITIONING, DEPTH AND HEIGHT CLEARANCE
All utility infrastructure within road reserves shall be clear of road carriageways and parallel or at right angles to the centreline of road carriageways unless otherwise agreed with the Superintendent.
Aerial services shall have a minimum height clearance of 5.5m above the finished road surface level or the natural surface. Poles for aerial services shall have a minimum lateral clearance of 3m from the edge of carriageway in urban areas and 9m in rural areas, except where frangible poles are used.
Unless otherwise shown on the drawings or specified, utility infrastructure and associated conduits installed under road carriageways for freeways and arterial roads shall be at depths to provide the following cover over the top of the infrastructure (including conduit):
(a)1200mm minimum cover to the finished road surface level; and
(b)750mm minimum cover to the invert level of road carriageway open drains.
706.04BORING UNDER CARRIAGEWAYS
Unless otherwise specified or approved by the Superintendent, all utility infrastructure (including conduits) under road carriageways shall be installed by boring.
Detailed proposals for boring under carriageways or alternative underground methods proposed by the Contractor shall be submitted to the Superintendent for review two weeks prior to the programmed commencement of work.
Unless otherwise specified, boring by water jetting will not be permitted.
Unless otherwise specified, the annulus between the bore and the pipe or carrier-conduit shall be filled by pressure grouting.
706.05EXCAVATION
Where the open trench method of crossing under a carriageway pavement is accepted, the line of the trench shall be straight, at right angles to the carriageway, and form the shortest link between terminals wherever practical. The width of trench shall be not greater than that necessary to carry out the work.
The edges of all trenches located within a road pavement shall be sawcut.
Any infrastructure located within the road reserve that is disturbed as a result of the work shall be reported immediately to the Superintendent and shall be reinstated promptly in consultation with the relevant infrastructure manager.
706.06MATERIALS
Unless otherwise specified, materials used for bedding and backfilling shall be uniform in composition and free from perishable matter and shall comply with the requirements specified in Table706.061.
Table 706.061 Material Properties
Material / Sieve Size AS (mm) / Plasticity IndexPercentage Passing (by mass)
75.0 / 37.5 / 19.0 / 2.36 / 0.075 / min / max
Bedding / 100 / 1040 / 2 / 10
Selected backfill / 100 / 1040 / 5 / 20
Common backfill / 100 / 40100
Pavement material shall be as specified in Clause706.12 and shall comply with the requirements of the specified sections as applicable.
706.07BEDDING
Where specified in Clause706.12 that bedding is required, bedding shall be placed below, around and above the pipe or carrier-conduit for the full width of the trench. Not less than 25mm compacted depth of bedding shall be placed below, and not less than 150mm compacted depth of bedding shall be placed above, the pipe or carrier-conduit. Bedding shall be placed in layers not exceeding 150mm loose thickness and shall be compacted as specified.
706.08BACKFILLING
Unless otherwise specified or shown on the drawings, selected and common backfill shall be placed and compacted as follows under, around, and above the conduit after the sections are bedded:
(a)Conduits under Area to be Paved, including Shoulders and Verges
Where the trench has been excavated from the nominated or designed subgrade level or above, the trench shall be backfilled up to the nominated or designed subgrade level with selected backfill material placed and compacted in layers not exceeding 150mm loose thickness, and above that level with common backfill material.
Where the trench is excavated from below the nominated or design subgrade level, the trench shall be filled with selected backfill material placed and compacted in layers not exceeding 150mm loose thickness.
(b)Conduits under Area not to be Paved
The opening shall be backfilled with common backfill placed and compacted as specified in layers not exceeding 200mm loose thickness.
(c)Conduits through Existing Paved Areas including Shoulders and Verges
Unless otherwise specified or shown on the drawings, the opening shall be backfilled to the existing subgrade level with selected backfill material placed and compacted in layers not exceeding 150 mm loose thickness and the pavement material placed and compacted in layers not exceeding 100mm loose thickness using materials in accordance with Clause706.12 (b).
706.09COMPACTION STANDARDS
(a)Bedding and Backfill (except pavement)
Unless otherwise specified, bedding and backfill shall have during compaction a uniform moisture content within the range 85%to115% of the optimum moisture content as determined in the Standard compactive effort. For backfill of nominal size greater than 40mm the fraction of material passing the 37.5mm sieve shall have during compaction a uniform moisture content within the range 85%to115% of the optimum moisture content as determined for that fraction in the Standard compactive effort.
Bedding and backfill shall be compacted to refusal using hand held mechanical equipment.
Backfilling beneath areas to be paved shall be assessed for compaction in lots as defined in Section173. The number of tests per lot shall be three. Backfill, the whole of which passes the 37.5mm ASsieve, shall be compacted to a mean value of density ratio of not less than97%. The calculation of density ratio shall be based on Standard compactive effort. Alot shall consist of a single layer of work. Aminimum of 20% of all lots constructed shall be tested.
Detailed proposals for the compaction of backfill materials of nominal size greater than 40mm shall be submitted to the Superintendent for review before commencing work.
(b)Pavement
Unless otherwise specified, pavement material shall have during compaction a uniform moisture content within the range 85%to115% of the optimum moisture content as determined in the Modified compactive effort.
Pavement material shall be assessed for compaction in lots as defined in Section173. The number of tests per lot shall be three. All pavement layers shall be compacted to a mean value of density ratio not less than the percentage specified in Clause706.12(b). The calculation of density ratio shall be based on Modified compactive effort. All pavement layers shall be tested.
706.10CLEANING OF SITE
Surplus excavated material shall be removed from the road reserve. Areas affected by the work shall be restored to a condition similar to that which existed prior to the commencement of the work.
706.11MAINTENANCE OF PAVEMENT
The reinstated surface shall be maintained in a trafficable condition after the completion of backfilling. Additional pavement material shall be placed in the trench and compacted as specified where in paved areas settlement or loss of material from the surface exceeds 20mm measured from a straight edge laid across the top of the trench.
706.12SCHEDULE OF DETAILS
***(a)Bedding (Clause 706.07) - ##(strikethrough ‘Required’ or ‘Not Required’):Required/Not required
***(b)Pavement Material (Clause 706.06)
Pavement Layer / Material Type / Thickness(mm) / Density Ratio
(Modified)
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